Field of the Invention
The present invention relates to a fuel evaporative gas treatment device for a fuel tank, which is used in a vehicle including a combustion engine with a supercharger.
Description of Related Art
In some vehicles including a combustion engine with a supercharger, a fuel evaporative gas treatment device is provided which treats and recoveries fuel evaporative gas or fuel evaporative emission generated by evaporation of fuel (e.g., see JP Laid-open Patent Publication No. 2005-036757). The fuel evaporative gas treatment device includes a canister containing an adsorbent which adsorbs fuel evaporative gas, and fuel evaporative gas generated in a fuel tank is treated by the canister and then supplied to an air intake passage for the combustion engine.
In the combustion engine equipped with the supercharger, for example, the pressure in the air intake passage may become a positive pressure due to a supercharging pressure of the supercharger, so that intake air may flow from the air intake passage toward the canister. In a fuel evaporative gas treatment device disclosed in JP Laid-open Patent Publication No. 2005-036757, a one-way valve is provided on a passage which connects the canister and the fuel tank, thereby preventing backflow from the canister side to the fuel tank. However, in JP Laid-open Patent Publication No. 2005-036757, since pressurized air is introduced into the canister, it is necessary to increase the pressure resistance of the canister, and thus, the structure of the canister is rendered to be complicated.